Sensors
Freescale Semiconductor 43
MMA26xxKW
4.2.1.15 DSI Command #14
DSI Command ‘1110’ is not implemented. Th e device ignores all command formats with a command ID of ‘1110’.
4.2.1.16 Reverse Initialization Command
The Reverse Initialization Command is not implemented. The device ignores all command formats with a command ID of
‘1111’. The device ignores all command received on the BUSOUT pin.
4.3 Exception Handling
Table 59 summarizes the exception conditions detected by the device and the response for each exception.
Table 59. Exception Handling
Condition Description SST UResponse
Exception Self-Test
Request
Power On
Reset N/A Power Applied
Clear Command 1 1 0 – Reference Section 3.6
VREG
Under-Voltage N/A VREG < VPORCREG_f
– Device held in Reset.
– No response to DSI commands.
– Bus switch open within tBSOPEN.
– Device must be re-initialized when VREG returns above VPORCREG_r
VREGA
Under-Voltage N/A VREGA < VPORCREG_f
– Device held in Reset.
– No response to DSI commands.
– Bus switch open within tBSOPEN.
– Device must be re-initialized when VREGA returns above VPORCREGA_r
VHCAP
Under-Voltage
Transient
Disabled VHCAP < VPORCREG_f for less
than tHCAP_POR, ST Disabled 001– DSI Read Acceleration Data Short response = zero.
– DSI Read Acceleration Data Long response = normal.
– Device does not need to be re-initialized if VHCAP returns above
VPORHCAP_r before tHCAP_POR
Enabled VHCAP < VPORCREG_f for less
than tHCAP_POR, ST Enabled 011 – DSI Read Acceleration Data Short response = self-test data.
– DSI Read Acceleration Data Long response = self-test data.
– Device does not need to be re-initialized if VHCAP returns above
VPORHCAP_r before tHCAP_POR
VHCAP
Under-Voltage N/A VHCAP < VPORCREG_f for longer
than tHCAP_POR
– Device is Reset and will continue to Reset every tHCAP_POR until VHCAP
returns above VPORHCAP_r, or an internal supply under-voltage condition
occurs.
– No response to DSI commands.
– Bus switch open within tBSOPEN.
– Device must be re-initialized when VHCAP returns above VPORHCAP_r
Capacitor Test
Failure N/A
– Device is Reset and will continue to be reset every tPOR_CAPTEST until the
capacitor failure is removed.
– No response to DSI commands.
– Bus switch open within tBSOPEN.
– Device must be re-initialized when capacitor failure is removed.
DSI Frame
Timeout N/A VBUSIN < VTHF for longer than tTO
– Device is Reset and will continue to be reset every tTO until the BUSIN
voltage returns above VTHF or a supply under-voltage condit i on occurs.
– No response to DSI commands.
– Bus switch open within tBSOPEN.
– Device must be re-initialized when VBUSIN returns above VTHF
Fuse CRC
Fault
(Factory Array)
Disabled CRC failure detected in factory
programmed OTP array and the
LOCK_F bit is set. ST Disabled 100– DSI Read Acceleration Data Short response = zero.
– DSI Read Acceleration Data Long response = normal.
Enabled CRC failure detected in factory
programmed OTP array and the
LOCK_F bit is set. ST Enabled 110– DSI Read Acceleration Data Short respon se = zero.
– DSI Read Acceleration Data Long response = self-test data.
Fuse CRC
Fault
(User Ar r a y )
Disabled CRC failure detected in User pro-
grammed OTP array and the
LOCK_U bit is set. ST Disabled 100 – DSI Read Acceleration Data Short response = zero.
– DSI Read Acceleration Data Long response = normal.
Enabled CRC failure detected in User pro-
grammed OTP array and the
LOCK_U bit is set. ST Enabled 110– DSI Read Acceleration Data Short response = zero.
– DSI Read Acceleration Data Long response = self-test data.
Temperature
Out of Range
Disabled Temperature out of range, ST
Disabled. 100– DSI Read Acceleration Data Short response = zero.
– DSI Read Acceleration Data Long response = normal.
Enabled Temperature out of range, ST
Enabled. 110– DSI Read Acceleration Data Short response = zero.
– DSI Read Acceleration Data Long response = self-test data.
Self-Test
Enabled Enabled ST Enabled 1 1 0 – Internal self-test circuitry enabled.
– DSI Read Acceleration Data Short response = self-test data.
– DSI Read Acceleration Data Long response = self-test data.
Self-Test
Lockout Disabled 2 consecutive Disable Self-Test
DSI commands received. 000– Internal self-test circuitry disabled.
– Enable Self-Test DSI command does not enable Self-Test. Normal
response to Enable Self-Test DSI command except the ST bit is not set.
– DSI Clear command or Reset disables lockout.